Aerodynamic wind propulsion device having active and passive steering lines and method for controlling of such a device

ABSTRACT

An aerodynamic wind propulsion device is provided, particularly for watercraft, in form of an aerodynamic wing connected to a steering unit located below the aerodynamic wing via a plurality of tractive lines, at least one pair of two active steering lines being connected to the aerodynamic wing at two points in distance and being coupled to a drive unit at the steering unit, a tractive cable, a first end of the tractive cable being connected at the steering unit to at least two of the tractive lines and a second end of the tractive cable being connected to a base platform, the aerodynamic wing having an aerodynamic profile which generates an uplift force, and two passive steering lines are connected to each other to form a continuous passive steering line section passing through the steering unit in order to passively follow a deformation of the aerodynamic wing.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit under 35 USC §371 of PCT applicationPCT/EP2007/064270 havind an International Filing Date of Dec. 19, 2007.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT

Not Applicable

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

Not Applicable

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an aerodynamic wind propulsion device,particularly for watercrafts, comprising an aerodynamic wing beingconnected to a steering unit located below the aerodynamic wing via aplurality of tractive lines, at least one pair of two active steeringlines being connected to the aerodynamic wing at two points in distanceto each other and being coupled to at least one drive unit at thesteering unit, a tractive cable, a first end of the tractive cable beingconnected at the steering unit to at least two of the tractive lines anda second end of the tractive cable being connected to a base platform,the aerodynamic wing having an aerodynamic profile which generates anuplift force in the direction of the tractive cable when the airflowdirection is about perpendicular to the tractive cable.

A further aspect of the invention is related to a method for controllingan aerodynamic wind propulsion device, particularly for watercrafts,comprising the steps connecting an aerodynamic wing to a steering unitlocated below the aerodynamic wing via a plurality of tractive lines,connecting at least one pair of two active steering lines to theaerodynamic wing at two points in distance to each other and couplingsaid at least one pair of active steering lines to at least one driveunit at the steering unit, connecting a first end of a tractive cable atthe steering unit to at least two of the tractive lines and connecting asecond end of said tractive cable to a base platform, and applyingsteering forces to said at least one pair of active steering lines.Description of Related Art including information disclosed under 37 CFR1.97 and 1.98

The following patents and publications were cited in an InternationalSearch Resort against the priority application as defining the generalstate of the art which is not considered to be of particular relevance:WO2005/100147 A (Oct. 27, 2005); DE 10 2004 054097 A1 (May 11, 2006); GB2,096,946 A (Dec. 1, 1982); U.S. Pat. No. 7,287,481 B1 (Oct. 30, 2007).

Today, carbon-based fuels like diesel or heavy fuel oil (HFO) are usedas a key resource for propelling nautic vessels. Mostly, diesel enginesare used to provide the driving force for the vessels. With increasingcosts for such carbon-based resources it becomes attractive to applyalternative methods for providing the driving force for nautic vessels.

WO 2005/100147 A1 discloses a positioning device for controlling a wingelement which is connected via a tractive cable to a ship to serve asmain or auxiliary drive. Such propulsion systems based on wing elementsflying at high altitude and pulling the ship via a tractive forcerequire large-scale wing elements and the control of such wing elementsis a challenging task. In WO 2005/100147 A1 it is proposed to veer outor haul in the tractive cable in response to the flight condition of thewing element. Whereas by such a control mechanism a certain degree offlight control can be achieved, it is not sufficient to control the wingelement in all flight conditions, in particular when the wind changesits strength or direction significantly.

To improve steerability of such wing elements in difficult windconditions it is known from WO 2005/100148 A1 to couple a steering unitclose below the wing element via a number of control lines and toconnect the wing element to the nautic vessel via such a steering unitby a tractive cable extending between the nautic vessel and the steeringunit. By this, control of the wing element can be improved but it isstill a challenging task to control the wing element and specifically tosteer the flight path of the wing element.

WO 2005/100149 A1 proposes various sensors to improve control of a wingelement towing a nautic vessel. Whereas these and the former techniquesmay improve the steerability of aerodynamic wing elements it remainsstill a quite challenging task to efficiently steer an aerodynamic wingelement and control its flight path and conditions in an efficient way.

To improve steerability during starting and landing manoeuvres, WO2005/100150 proposes a telescopic mast erected onto the foredeck of thenautic vessel close to the fixing point of the tractive cable couplingthe wing element to the nautic vessel. Using such mast, the wing elementcan be directly coupled to the top of the mast. Whereas such a techniquemay significantly improve manoeuvrability of the wing element duringstarting and landing procedure, the challenging task to improve thesteerability of the wing element in various flight conditions and toimprove the efficiency of such a steering technique remains.

SUMMARY OF THE INVENTION

According to the invention, an aerodynamic wing for a watercraft isprovided, the aerodynamic wing being connected to a steering unitlocated below the aerodynamic wing via a plurality of tractive lines, atleast one pair of two active steering lines being connected to theaerodynamic wing at two points in distance to each other and beingcoupled to at least one drive unit at the steering unit, a tractivecable, a first end of the tractive cable being connected at the steeringunit to at least two of the tractive lines and a second end of thetractive cable being connected to a base platform, the aerodynamic winghaving an aerodynamic profile which generates an uplift force in thedirection of the tractive cable when the airflow direction is aboutperpendicular to the tractive cable.

Further according to the invention, a method for controlling anaerodynamic wing for a watercraft is provided, the method comprising thesteps of connecting an aerodynamic wing to a steering unit located belowthe aerodynamic wing via a plurality of tractive lines, connecting atleast one pair of two active steering lines to the aerodynamic wing attwo points in distance to each other and coupling said at least one pairof active steering lines to at least one drive unit at the steeringunit, connecting a first end of a tractive cable at the steering unit toat least two of the tractive lines and connecting a second end of saidtractive cable to a base platform and applying steering forces to saidat least one pair of active steering lines.

It is a first object of the present invention to provide a devicefacilitating and improving the control and/or steerability of anaerodynamic wing.

It is a further object of the invention to improve the load-bearingdistribution and force transmission within and across the device.

It is a further object of the invention to improve the efficiency of thedevice.

According to a first aspect of the invention, an aerodynamic windpropulsion device as mentioned above is provided, characterized by apair of two passive steering lines, wherein each of the two passivesteering lines comprises a lower section and an upper section, wherein asecond end of the lower section of each passive steering line isconnected to a first end of the upper section of the respective passivesteering line via a connecting member, second ends of the upper sectionsof the two passive steering lines are connected to the aerodynamic wingat two points in distance to each other, and first ends of the lowersections of the two passive steering lines are connected to each otherin the region of the steering unit to form a continuous passive steeringline section passing through the steering unit in order to passivelyfollow a deformation of the aerodynamic wing induced by steering forcesapplied to said at least one pair of active steering lines.

The aerodynamic wind propulsion device according to the inventionconsists of several entities that are coupled or connected to eachother. The term connected is used in this context to have the meaningthat the two entities being connected are directly or indirectlysecured, fastened or attached to each other. An indirect connection mayfurther comprise a connecting element or connecting member thatphysically establishes the connection between the entities. The termcoupled is used in the present context to describe a functionalrelationship or engagement, respectively, between the coupled elementssuch that an element coupled to another element has an effect on theother element, e.g. a gear to a toothed belt or a pulley to a belt.

The tractive lines of the aerodynamic wind propulsion device primarilyaccommodate forces resulting from the uplift force generated by theaerodynamic profile of the aerodynamic wing. These tractive forces aretransferred to the tractive cable via the steering unit, thus connectingthe base platform to the aerodynamic wing via the tractive lines, thesteering unit and the tractive cable.

The aerodynamic wing is formed in an aerodynamic profile to thusgenerate the uplift force and may be formed as a hollow body and maycomprise one or more openings in order to allow an air stream to enterand/or leave the interior of the aerodynamic wing and inflate and/ordeflate the aerodynamic profile, respectively.

The steering lines function as means for controlling and changing thegeometry of the aerodynamic wing and consequently affects its flightdirection or properties, respectively, thus allowing to steer the flightpath of the aerodynamic wing. The at least one drive unit located at thesteering unit is coupled to at least one pair of active steering lines,such that an activation of the at least one drive unit results inshortening and/or lengthening of said two active steering lines. Thisway steering forces can be applied to the active steering lines andtransferred to the aerodynamic wing in order to change its orientationand/or flight direction or properties, respectively. It is to beunderstood that the two active steering lines may be formed by a singlecontinuous active steering line running through or adjacent to thesteering unit.

The term active is used in this context to describe that the steeringlines are coupled to a drive unit that can be driven to apply steeringforces to the active steering lines in order to shorten and/or lengthenthe active steering lines on one side and/or the other side of the driveunit, respectively, and transfer the steering forces to the aerodynamicwing. In the context of this application, shortening a line isequivalent to hauling in that line and lengthening a line is equivalentto veering out that line. The steering lines can be coupled to the driveunit directly, via a gear or via a pulley or via other coupling means.

The aerodynamic wind propulsion device according to the first aspect ofthe invention further comprises a pair of passive steering lines withtheir lower sections preferably connected to each other to form acontinuous passive steering line section. The term passive in thiscontext indicates, that basically no directly and actively appliedforces are transferred to these lines via a driven unit. Primarily,forces are accommodated or movements performed as a passive reaction toforces or movements applied or generated by the deformation of theaerodynamic wing itself. Thus, other than the active steering lines, thecontinuous passive steering line section typically is not coupled to adrive unit applying steering forces.

The continuous passive steering line section consists of the two lowersections of the pair of two passive steering lines, said two lowersections being connected to each other with their first ends so thatthey form a continuous passive steering line section extending throughor along the steering unit or a pulley or the like connected to thesteering unit. The upper sections of the two passive steering lines areconnected with their ends to the second ends of the respective lowersections of the two passive steering lines. The second ends of the uppersections of the passive steering lines are connected to the aerodynamicwing at two points in distance. In this way these two points in distanceat the aerodynamic wing are connected to each other via the uppersections of the two passive steering lines and the continuous passivesteering line section formed by the lower sections of said two passivesteering lines. It is to be understood that all the passive steeringline sections are preferably formed by one continuous passive steeringline.

Thus, in case the aerodynamic wing changes its orientation and/or flightdirection or properties, respectively, such that one of said two pointsin distance at the aerodynamic wing changes its location in respect tothe other one of the two points in distance, the continuous passivesteering line section accommodates and assists for this change bypassively following the movements and/or deformation of the aerodynamicwing. These movements and/or deformation of the aerodynamic wing may atleast partially result from the steering forces that are applied to theactive steering lines and transferred to the aerodynamic wing. Thus,while the active steering lines transfer the steering forces that areapplied by the drive unit to the aerodynamic wing, the passive steeringlines primarily accommodate forces resulting from a deformation of theaerodynamic wing and passively mirror the shortening and/or lengtheningof the active steering lines, in order to passively follow the movementand deformation of the aerodynamic wing. When the orientation of theaerodynamic wing and/or its flight direction or properties,respectively, are stable and no steering forces are applied to theactive steering lines, the passive steering lines are substantially freeof passive steering forces but may accommodate tractive forces resultinge.g. from the uplift force generated by the aerodynamic profile of theaerodynamic wing.

The invention may be improved in that the at least one continuouspassive steering line section is guided via a passive pulley located atthe steering unit. The pulley may also be located close to the steeringunit. A passive pulley in this context is understood as a pulley thatcan be rotated by a line that is guided via said pulley, but does notactively apply frictional forces to the line in order to shorten orlengthen the line on one side with respect to the pulley. In the currentembodiment a passive pulley is used to guide the continuous passivesteering line section at the steering unit, to transfer uplift forcesand to allow the continuous passive steering line section to passivelyfollow a deformation of the aerodynamic wing.

According to a further aspect of the invention, an aerodynamic windpropulsion device as mentioned above or described in the introductoryportion of this description is provided, that is characterized in thatthe first end of the tractive cable is directly secured to a connectingelement, e.g. a bolt or a pulley, located at the steering unit, and inthat at least one of the tractive lines is also directly secured to saidconnecting element, and said connecting element is adapted to transfertractive forces between the tractive cable and said at least onetractive line.

According to this embodiment the load-bearing distribution and forcetransmission at the steering unit is improved. The tractive forcesacting on the steering unit execute significant internal stress onto thesteering unit, when the tractive cable is attached to one point at thesteering unit and the tractive lines are attached to one or moredifferent points at the steering unit that are distant from theattachment point of the tractive cable, because in such an arrangementthe tractive forces have to be transferred from the tractive linesthrough the steering unit to the tractive cable. According to thecurrent aspect of the invention, this disadvantage is overcome bydirectly fastening the tractive cable as well as at least one of thetractive lines to one common connecting element located at the steeringunit. In this way the tractive forces between the tractive cable and theat least one tractive line may be transferred via the connecting elementinstead of being transferred across a part of the steering unit or thewhole unit. The connecting element may take the form of a bolt, pulley,anchor, ring, lug or the like and may consist of a special material thatis suitable to accommodate and transfer high forces.

The invention may be further improved in that the tractive cable and theat least one tractive line are wound around said connecting element. Inorder to provide a secure high-strength connection between the tractivecable, the at least one tractive line and the connecting element, it ispreferred, that both the tractive cable and the at least one tractiveline are wound around the connecting element. In this case the tractivecable or the at least one tractive line, respectively, may form a smallloop or spiral around the connecting element. After winding the tractivecable and the at least one tractive line around the connecting element,the loose ends of the tractive cable and the at least one tractive linemay be securely fastened to either the connecting element or to theremaining part of the tractive cable or the at least one tractive line,respectively.

According to a further aspect of the invention, an aerodynamic windpropulsion device as mentioned above or described in the introductoryportion of this description is provided, wherein each of the two activesteering lines comprises a lower section and an upper section, wherein asecond end of the lower section and a first end of the upper section areconnected to each other via a connecting member, and a second end of theupper section is connected to the aerodynamic wing at one of the twopoints in distance, and first ends of the two lower sections of the twoactive steering lines are connected to each other in the region of thesteering unit to form a continuous active steering line section that iscoupled to the at least one drive unit and passing through the steeringunit, and that is characterized in that a first relieve line is guidedvia a first relieve line pulley located at the steering unit, a firstend of the first relieve line is connected to the connecting member ofone of the two active steering lines, and a second end of the firstrelieve line is connected to the connecting member of the other one ofthe two active steering lines.

In this embodiment a continuous active steering line section is providedin a similar manner as for the continuous passive steering line sectiondescribed above. First ends of the two lower sections of the two activesteering lines are fastened to one another and form the continuousactive steering line section that is coupled to the at least one driveunit so that—other than the continuous passive steering line section—theat least one drive unit can apply forces to the continuous activesteering line section. The drive unit may be coupled to the continuousactive steering line section via a driven pulley. The drive unit mayexert steering forces to the continuous active steering line section,preferably via the pulley, in order to shorten the continuous activesteering line section with respect to one side and lengthen thecontinuous active steering line section with respect to the other sideof a symmetry axis of the steering unit or the aerodynamic wing,respectively.

It is preferred that the aerodynamic wing and the steering unit each arebasically formed symmetrically to a symmetry axis and that the symmetryaxis of the steering unit and that of the aerodynamic wing substantiallyfall together thus forming a common symmetry axis. It is furtherpreferred that also the arrangement of the lines connecting theaerodynamic wing to the steering unit is largely symmetric to thatcommon symmetry axis. Shortening and lengthening a line thatcontinuously passes through the steering unit on one side with respectto said symmetry axis therefore results in a respective lengthening orshortening of that line on the other side of said symmetry axis.

The second ends of the lower sections of the two active steering linesare attached to respective first ends of the upper sections of the twoactive steering lines via connecting members and the second ends of theupper sections of the two active steering lines are attached to twopoints in distance at the aerodynamic wing. Thus, these two points indistance at the aerodynamic wing are connected to each other via a loopformed by the upper sections of the two active steering lines and thecontinuous active steering line section consisting of the two lowersections of the two active steering lines. Therefore, the steeringmechanism may activate these two points at the aerodynamic wing withrespect to each other. For example, if the drive unit lengthens thecontinuous active steering line section with respect to one side of thesymmetry axis, this results in an accordant shortening of the continuousactive steering line section with respect to the other side of thesymmetry axis. Thus, the two points in distance of the aerodynamic wingcan be steered reciprocally.

The current embodiment also provides for a first relieve line that maybe basically parallel to the continuous active steering line section.The ends of the first relieve line are preferably connected to said twoconnecting members, that connect the upper and lower sections of the twoactive steering lines. Alternatively, the ends of the first relieve linecan be connected to the continuous active steering line section or theupper sections of the two active steering lines. The first relieve lineis guided via a first relieve line pulley that is preferably located ator close to the steering unit.

In the context of the present invention, the first relieve line may be aline accommodating steering forces, forces resulting from the upliftforce generated by the aerodynamic profile of the aerodynamic wingand/or forces resulting from a deformation of the aerodynamic wing.Thus, the first relieve line can act as a further active steering line,as a further passive steering line or as a further tractive line. If thefirst relieve line is used as a further steering line, the requiredsteering forces may be split between the continuous active steering linesection and the first relieve line.

In another case the first relieve line may not accommodate appliedsteering forces, but may accommodate forces resulting from the upliftforce generated by the aerodynamic profile of the aerodynamic wing(especially if it serves as a further tractive line), and/or forcesresulting from a deformation of the aerodynamic wing (especially if itserves as a further passive steering line). This case has the advantage,that the first relieve line accommodates forces other than appliedsteering forces and thus the continuous active steering line section mayprimarily only accommodate applied steering forces. In this way, thecontinuous active steering line section can be relieved from forcesother than applied steering forces. Thus, the drive unit does not haveto apply the steering forces against at least a part of the forcesresulting from the uplift force generated by the aerodynamic profile ofthe aerodynamic wing and/or resulting from a deformation of theaerodynamic wing that are accommodated by the first relieve line.

This embodiment can be further improved in that the first relieve linepulley and the at least one drive unit are located at distant points atthe steering unit.

It is preferred, that the first relieve line pulley and the at least onedrive unit are spaced apart. It is particularly preferred, that thedrive unit is located above the first relieve line pulley or vice versain operational position of the device. Also, the active steering linesection may be located above the first relieve line or vice versa.

The invention can be further improved in that the aerodynamic wing isconnected to the connecting members of the two active or passivesteering lines, respectively, via at least one further steering line orsteering line section, respectively. It is preferred, that theaerodynamic wing is attached to the two steering lines not only via saidupper line sections at said two points in distance but via a pluralityof lines or line sections, respectively, at a plurality of points. It isespecially preferred, that two groups of more than two lines or linesections, respectively, each are provided being connected to theaerodynamic wing at two groups of points, the two groups of points beinglocated in the proximity of the two points in distance at theaerodynamic wing. It is further preferred that each of the steeringlines or line sections, respectively, is connected to the connectingmember of the respective active or passive steering line. Thisarrangement provides a plurality of upper steering line sections thatare merged into one lower steering line section via the respectiveconnecting member. This arrangement has the advantage, that the forcestransferred via the steering lines are concentrated in the lowersteering line sections but fan out towards a plurality of points at theaerodynamic wing and thus distribute the steering forces to theseseveral points. This is particularly preferred in order to reduce thestress occurring at single points at the aerodynamic wing. Further, thiscan improve steerability of the aerodynamic wing, because a larger areaof the aerodynamic wing is addressed via a plurality of points.

A further preferred embodiment of the invention is characterized in thata second relieve line is guided via a second relieve line pulley locatedat the steering unit, a first end of said second relieve line isconnected to the connecting member of one of the two active steeringlines, and a second end of said second relieve line is connected to theconnecting member of the other one of the two active steering lines.This embodiment provides for a second relieve line, that can bebasically parallel to the first relieve line and/or the continuousactive steering line section. Similar to the first relieve line, theends of the second relieve line may be connected to the connectingmembers connecting the respective upper and lower sections of the twoactive steering lines or to the continuous active steering line sectionor the upper sections of the two active steering lines. The secondrelieve line pulley that guides the second relieve line is preferablylocated at the steering unit between the first relieve line pulley andthe at least one drive unit, above those two elements or below them. Thesecond relive line pulley may alternatively be located close to thesteering unit.

Similar to the first relieve line, the second relieve line may serve asa further active steering line, as a further passive steering line, oras a further tractive line, as described above with respect to the firstrelieve line.

It is preferred that the first and second relieve lines have differentfunctions, e.g. the first relieve line serves as a second activesteering line and the second relieve line serves as a further passivesteering line and/or further tractive line. This way the advantages ofthe different functions of the relieve lines can be combined.

The invention can be further improved in that a pair of two steeringlines or lower sections of a pair of two steering lines, respectively,are connected to each other in the region of the steering unit to formthe relieve line or one of the relieve lines, respectively. Thisembodiment is particularly preferred in order to reduce the number oflines of the aerodynamic wind propulsion device. Especially if therelieve line or one of the relieve lines serves as a steering line, itis advantageous to form the relieve line or one of the relieve lines byconnecting the lower sections of a pair of two existing steering linesto each other. In case that the relieve line or one of the relieve linesserves as a tractive line, the relieve line or one of the relieve linesmay be formed by the lower sections of a pair of two tractive lines,which are connected to each other in the region of the steering unit.

The invention can be further improved in that one of the relieve linepulleys is located coaxially to the at least one drive unit at thesteering unit. Thus, one of the relieve lines and the continuous activesteering line section may be guided parallel to each other. Thisembodiment can also save space at the steering unit.

The invention can be further improved in that at least one of therelieve line pulleys is a passive pulley. The term passive pulley isused in this context with the connotation described above. Thisembodiment is particularly preferred in the case that the relieve lineor one of the relieve lines, respectively, serves as a passive steeringline or a tractive line.

In case that a relieve line serves as further active steering line, thepulley may be coupled to a drive unit and thus not be a passive pulleyor the relieve line serving as an active steering line may be coupled toanother means for applying steering forces. It is possible, that—in casethere are two relieve lines—only one of the relieve lines is guided viaa passive pulley or that both of the relieve lines are guided via apassive pulley each.

The embodiment can be further improved in that the first relieve linepulley is coupled to a second drive unit such that activation of atleast one of the drive units results in shortening the continuous activesteering line section or the first relieve line, respectively, withrespect to one side and lengthening the continuous active steering linesection or the first relieve line, respectively, with respect to theother side of a symmetry axis of the steering unit or the aerodynamicwing, respectively.

In this embodiment, the first relieve line may serve as an activesteering line, and be coupled to a second drive unit. The second driveunit may be able to apply steering forces to the first relieve line. Thesecond drive unit may be coupled to the first relieve line via a pulley,preferably via said first relieve line pulley. In this case the firstrelieve line pulley is an actively driven pulley. In this arrangement,the relieve line can be hauled in and veered out with respect to thesides of the symmetry axis on the steering unit or the aerodynamic wing,respectively.

The continuous active steering line section is coupled to the firstdrive unit, which applies steering forces to the continuous activesteering line section such that the continuous active steering linesection can be veered out and hauled in with respect to the sides of thesymmetry axis of the steering unit or the aerodynamic wing,respectively.

The ends of the first relieve line and the continuous active steeringline section may be connected to common connecting members thus forminga circular line so that the forces applied to the first relieve line andthe forces applied to the continuous active steering line section canadd up to a total steering force acting on the aerodynamic wing via theconnecting members and the upper steering line sections. It isparticularly preferred that both drive units apply steering forces in acoordinate manner. Therefore it is preferred that the activation of thedrive units results in either a shortening of both the first relieveline and the continuous active steering line section with respect to oneside of the symmetry axis of the steering unit or the aerodynamic wing,respectively, or in a lengthening of both the first relieve line and thecontinuous active steering line section with respect to that side of thesymmetry axis and vice versa with respect to the other side of thesymmetry axis. Depending on the arrangement of the lines with respect tothe drive units, this can require both drive units to be driven in thesame or in opposite directions to achieve acting of them in the samedirection.

The invention can be further improved in that each of the drive unitscomprises a blocking device adapted to actively block, particularly in amechanical manner, the respective drive unit in case of its failure.

In case of failure of a drive unit, e.g. due to breakage or malfunction,it is preferred that this driving unit is immediately blocked andprevented from operating or being turned e.g. by a fastening bolt, breakor the like. It is further preferred that the respective line that isguided via said failed drive unit is prevented from moving, i.e. beingshortened or lengthened with respect to one side or the other of thesymmetry axis, for example by providing a clamp, draw roll, stopper,bracket or a fastener and activating it in case of the failure of thedrive unit. In such case, steering forces can be applied by theremaining other drive unit, providing save-to-fail redundancy.

A further preferred embodiment is characterized in that the continuousactive steering line section and the first relieve line are connected toeach other to form a loop. The invention can be further improved in thatthe connecting member of at least one of the two active steering lines,preferably both, comprises a pulley, and said loop is guided via saidpulley. Providing a loop or a continuous belt has the advantage, thatproblems occurring in transferring the forces at the end of lines andtheir connections can be avoided. Further, providing such a loop meansthat the function of the continuous active steering line section and therelieve line may be selected to be similar to thus provide redundancyand sharing of forces.

Preferably, the loop is formed by one continuous line, particularly acontinuous belt. In addition it is preferred, that the loop is guidedvia two active devices at the steering unit that preferably areidentical with the at least one drive unit and the first relieve linepulley, that is an active pulley coupled to a drive unit in this case.

The provision of two drive units is particularly preferred foractivating said loop since a redundancy of the activation is provided.This arrangement is particularly useful, since the activation of theloop can be maintained in case of the failure of one of the drive units.In this case only the steering force of the remaining drive unit isapplied. In this embodiment it is particularly preferred that each ofthe drive units includes a blocking device that is adapted to block therespective drive unit in case of its failure. This is particularlyuseful since in case of the absence of such blockage the loop orcontinuous belt may run through the pulley(s) without exerting asteering force onto the aerodynamic wing via the upper steering linesections and connecting members in case of the failure of one of thedrive units.

The invention can be further improved in that one of said drive units islocated below the other one at the steering unit, both drive units arecoupled to drive pulleys located within the loop, and the loop ispreferably pressed against the upper drive pulley by two guiding pulleyslocated at the steering unit.

In this embodiment it is further preferred, that the loop is pressedagainst at least one of the two drive units by two pulleys, particularlydraw rolls, located on either side of the drive unit at the steeringunit. This is particularly preferred for the upper drive unit with theloop passing on the upper side.

When the loop is acting as an active steering means, it is preferredthat a second relieve line is provided and that said second relieve lineserves as a further passive steering line or tractive line. In thisarrangement it is further particularly preferred, that the secondrelieve line is guided by a second relieve line pulley located at thesteering unit between said two drive units. In this preferred embodimentthe activation of the loop is facilitated, since a part of the forces,particularly forces resulting from the uplift force generated by theaerodynamic profile of the aerodynamic wing and/or forces resulting froma deformation of the aerodynamic wing, are relieved from the loop andaccommodated by the second relieve line. Thus, the drive units facesless forces against which the steering forces have to be applied.

In a further aspect, the invention may be embodied in a watercraft,comprising an aerodynamic wind propulsion device as described above. Inthis respect, reference is made to the international applicationsmentioned in the introduction of this description describing suchsystems for towing a watercraft.

Further, the invention may be embodied in the use of an aerodynamic windpropulsion device as described above to propel a watercraft.

According to a further aspect of the invention, a method for controllingan aerodynamic wind propulsion device, as described in the introductorypart of this description, is provided, that is characterized by thesteps of providing a pair of two passive steering lines, each of the twopassive steering lines comprising a lower section and an upper section,connecting a second end of the lower section of each passive steeringline to a first end of the upper section of the respective passivesteering line via a connecting member, connecting second ends of theupper sections of the two passive steering lines to the aerodynamic wingat two points in distance to each other, and connecting first ends ofthe lower sections of the two passive steering lines to each other inthe region of the steering unit to form a continuous passive steeringline section passing through the steering unit. The method according tothe invention can be improved by the step of guiding the at least onecontinuous passive steering section line via a passive pulley located atthe steering unit.

According to a further aspect of the invention, a method for controllingan aerodynamic wind propulsion device, as mentioned above or describedin the introductory portion of this description is provided, that ischaracterized by the steps of directly securing the first end of thetractive cable to a connecting element, e.g. a bolt or a pulley, locatedat the steering unit, directly securing at least one of the tractivelines to said connecting element, and transferring tractive forcesbetween the tractive cable and said at least one tractive line via saidconnecting element. The method according to the invention can beimproved by the step winding the tractive cable and the at least onetractive line around said connecting element.

According to a further aspect of the invention, a method for controllingan aerodynamic wind propulsion device, as mentioned above or describedin the introductory portion of this description, is provided, comprisingthe steps of providing each of the two active steering lines with alower section and an upper section, connecting second ends of the lowersections and first ends of the respective upper sections to each othervia a connecting members, and connecting second ends of the uppersections to the aerodynamic wing at the two points in distance, andconnecting first ends of the two lower sections of the two activesteering lines to each other in the region of the steering unit to forma continuous active steering line section that is coupled to the atleast one drive unit and passing through the steering unit, and that ischaracterized by the steps guiding a first relieve line via a firstrelieve line pulley located at the steering unit, connecting a first endof the first relieve line to the connecting member of one of the twoactive steering lines, and connecting a second end of the first relieveline to the connecting member of the other one of the two activesteering lines.

The method according to the invention can be improved by the steps ofprimarily accommodating applied steering forces by the active steeringlines or continuous active steering line section, respectively, andprimarily accommodating steering forces, forces resulting from theuplift force generated by the aerodynamic profile of the aerodynamicwing and/or forces resulting from a deformation of the aerodynamic wingby the first relieve line. The method according to the invention can befurther improved as described in claims 25-31.

As to the advantages, preferred embodiments and details of these furtheraspects and preferred embodiments, reference is made to thecorresponding aspects and embodiments described above.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention shall now be described withreference to the attached drawings, in which

FIG. 1: shows a schematic partial view of a first embodiment of theinvention with a steering unit, a pair of active steering lines, a pairof passive steering lines and a pair of tractive lines,

FIG. 2: shows a schematic view of a detail of a second embodiment of theinvention with a steering unit and a connecting element to transfertractive forces,

FIG. 3: shows a schematic view of a detail of a third embodiment of theinvention with a steering unit, a continuous active steering linesection and a relieve line, and

FIG. 4: shows a schematic partial view of a fourth embodiment of theinvention with an aerodynamic wing, a steering unit, two drive units anda loop.

FIG. 5: shows a perspective view of an aerodynamic wing attached viaplurality of lines to gondola that is tethered via a tractive cable to abase platform of a vessel.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 schematically shows a part of a first embodiment of the presentinvention, comprising a steering unit 100 in a gondola 1.2 (FIG. 5) thatis connected to an aerodynamic wing (not shown) 101 via a plurality oflines 101-106 (FIG. 1), including one or more steering line components1.3 (FIG. 5). This arrangement of a plurality of lines 101-106 will bedescribed in further detail below. The gondola 1.2 is attached via atractive cable 1.1 to an anchor 2 on a base platform 3 of a vessel 4.

A pair of active steering lines 101 a, 102 a, 101 b, 102 b is provided.Each of the two active steering lines 101 a, 102 a and 101 b, 102 bconsists of a lower section 101 a, b and an upper section 102 a, b. Thelower sections 101 a, b of the two active steering lines are connectedto each other in the region of the steering unit 100 thus forming onecontinuous active steering line section 101 a, b passing through thesteering unit 100. The continuous active steering line section 101 a, bis connected to the upper sections 102 a, b via connecting members 150a, b. The upper sections 102 a, 102 b are connected to an aerodynamicwing (not shown) at two points in distance. The upper line sections 102a, b are provided as a total of four load sharing line sections 102 a, beach being connected with first ends to the connecting members 150 a, band with second ends to a plurality of adjacent points at theaerodynamic wing (not shown). As can be seen from FIG. 1, the pluralityof further upper line sections 102 a, b is divided into two groups, eachgroup defining said upper line sections 102 a, b for said lower linesections 101 a, b.

The continuous active steering line section 101 a, b is coupled to adrive unit 120 at the steering 100. The drive unit 120 may comprise adriven pulley that is coupled to an electric servo motor, wherein saidmotor activates the driven pulley to rotate in one or the otherdirection and thus moves the continuous active steering line section 101a, b in the respective direction. The activation of the drive unit 120in a counter-clockwise direction results in a shortening of thecontinuous active steering line section 101 a, b on the left hand sideof the symmetry axis 110 of the steering unit 100 and a respectivelengthening of the continuous active steering line section 101 a, b onthe right hand side of the symmetry axis 110. Vice versa, activation ofthe drive unit 120 in a clockwise direction produces a shortening of thecontinuous active steering line section 101 a, b on the right hand sideof the symmetry axis 110 and a lengthening of the continuous activesteering line section 101 a, b on the left hand side of the symmetryaxis 110.

Further, a pair of passive steering lines 103 a, 104 a and 103 b, 104 bis provided. Each of the two passive steering lines 103 a, 104 a and 103b, 104 b comprises a lower passive steering line section 103 a, b and anupper passive steering line section 104 a, b. The two lower passivesteering line sections 103 a, b are connected to each other to form acontinuous active steering line section 103 a, b. The upper passivesteering line sections 104 a, b are connected to the ends of thecontinuous passive steering line section 103 a, b via connecting members151 a, b. The upper passive steering line sections 104 a, b areconnected to two points in distance at the aerodynamic wing (not shown).A total number of four upper passive steering line sections 104 a, b areprovided on each side and connected via the connecting members 151 a, bto the lower passive steering line section 103 a, b. Each group of fourupper passive steering line sections 104 a, b is secured at theaerodynamic wing. The continuous passive steering line section 103 a, bis guided via a passive pulley 130 which is located in the proximity ofthe steering unit 100 and connected to the steering unit 100.Alternatively, the passive pulley 130 may be located directly within thesteering unit 100.

A pair of tractive lines 105 a, 106 a and 105 b, 106 b is provided. Thetwo tractive lines 105 a, 106 a and 105 b, 106 b consist of lowertractive line sections 105 a, b and upper tractive line sections 106 a,b. The lower sections 105 a, b are connected to the respective uppertractive line sections 106 a, b via connecting members 152 a, b. Thelower right tractive line section 105 a is fastened to the steering unit100 at a fixing point 140 a and the left lower tractive line section 105b is fastened to the steering unit 100 at a fixing point 140 b. Theupper tractive line sections 106 a, b are connected to the aerodynamicwing (not shown) at two points in distance and are provided as two loadsharing lines 106 a, b, each.

The pair of tractive lines primarily accommodates forces resulting fromthe uplift force generated by the aerodynamic profile of the aerodynamicwing. The arrangement of the active steering lines comprising thecontinuous active steering line section 101 a, b and the plurality ofupper active steering line sections 102 a, b transfers steering forcesapplied by the drive unit 120 to the aerodynamic wing.

The arrangement of passive steering lines comprising the continuouspassive steering line section 103 a, b and the plurality of upperpassive steering line sections 104 a, b passively follows the movementsand/or deformation of the aerodynamic wing (not shown), induced by thesteering forces applied via the active steering lines to the aerodynamicwing. This is realized by the passive pulley 130, which allows thecontinuous passive steering line section 103 a, b to execute ashortening on the left hand side of the symmetry axis 110 and arespective lengthening on the right hand side of the symmetry axis 110and a lengthening on the left hand side of the symmetry axis 110 and arespective shortening on the right hand side of the symmetry axis 110following symmetrically the respective lengthening and shortening of thecontinuous active steering line section 101 a, b.

In this way the applied steering forces are directly transferred to afirst plurality of points at the aerodynamic wing, where the pluralityof upper active steering line sections 102 a, b are connected, andpassively transferred to a plurality of connection points at theaerodynamic wing, where the plurality of upper passive steering linesections 104 a, b is connected to the aerodynamic wing.

FIG. 2 shows a schematic view of a detail of a second embodiment of thepresent invention with a steering unit 200, a pair of steering lines 201a, b, a pair of tractive lines 205 a, b and a tractive cable 207. Thearrangement is symmetric with respect to a symmetry axis 210 of thesteering unit 200. The pair of steering lines 201 a, b is guided via apulley 220, that may be coupled to an electric motor in case thesteering lines 201 a, b are active steering lines. The two tractivelines 205 a, b are directly secured to a coupling element 260, that isadapted to transfer tractive forces from the tractive lines 205 a, b tothe tractive cable 207. The tractive cable 207 is also directly securedto said connecting element 260. This embodiment has the advantage, thatthe tractive forces are directly transferred via the connecting element260 from the tractive lines 205 a, b to the tractive cable 207, suchthat the steering unit 200 does not have to be dimensioned toaccommodate and transfer these tractive forces across the steering unit200. In this way it is possible to save weight of the steering unit 200which is advantageous in respect to its flying properties.

The two steering lines 201 a, b may be connected to form a continuoussteering line or continuous steering line section, respectively, that isguided via the pulley 220 or they may be connected to the pulley 220each. The tractive lines 205 a, b may be connected to form a continuoustractive line, that is wound around the connecting element 260 or theymay be directly secured to the connecting element 260 each. Theconnecting element 260 may take the form of a bolt, anchor, ring, lug orthe like and may consist of a special material that is suitable toaccommodate and transfer high forces.

FIG. 3 shows a schematic view of a detail of a third embodiment of thepresent invention with a steering unit 300 with a symmetric axis 310, apair of active steering lines 302 a, 301 a and 302 b, 301 b, and arelieve line 370 a, b. The pair of active steering lines consists of twoactive steering lines 302 a, 301 a and 302 b, 301 b with lower activesteering line sections 301 a, b and upper active steering line sections302 a, b, that are connected to the respective lower active steeringline sections 301 a, b via the connecting members 350 a, b. The loweractive line sections 301 a, b are connected to each other in order toform a continuous active steering line section 301 a, b that is guidedvia a driven pulley 320 that is coupled to a drive unit (not shown).

The relieve line consists of two sections 370 a, b that are connected toeach other in order to form one continuous relieve line 370 a, b that isguided via a passive pulley 330 located at the steering unit 300. Therelieve line 370 a, b is also connected to the connecting elements 350a, b.

In this arrangement the relieve line 370 a, b acts as a passive line,accommodating primarily forces resulting from the uplift force generatedby the aerodynamic profile of the aerodynamic wing and/or forcesresulting from a deformation of the aerodynamic wing. The continuousactive steering line section 301 a, b primarily accommodates steeringforces applied by the drive unit that is coupled to the continuousactive steering line section 301 a, b via the driven pulley 320. Anactivation of the pulley driven 320 via the drive unit results inshortening the continuous active steering line section 301 a, b on theleft hand side of the symmetry axis 310 and lengthening the continuousactive steering line section 301 a, b on the right hand side of thesymmetry axis 310 or vice versa, depending on the direction oforientation of the driven pulley 320. The relieve line 370 a, bpassively follows this shortening and/or lengthening accordingly via thepassive pulley 330.

FIG. 4 schematically shows a part of a fourth embodiment of the presentinvention with an aerodynamic wing 480, a steering unit 400 and a commonsymmetry axis 410 of the steering unit 400 and the aerodynamic wing 480.Two driven pulleys 420 and 421 are located at the steering unit 400.Each of the two driven pulleys 420, 421 is coupled to an electric motor(not shown). Between the two driven pulleys 420, 421 a passive pulley430 is located. A relieve line 470 a, 470 b is connected to a firstconnecting element 450 a and a second connecting element 450 b. Theseconnecting elements 450 a, b are connected to the aerodynamic wing 480via four upper line sections 402 a, b. The connecting members 450 a, beach comprise a pulley 453 a, b. A continuous belt or loop consisting ofthe sections 401 a, b and 401 c, d is coupled to the two driven pulleys420 and 421 at the steering unit 400 and guided via the two pulleys 453a, b located at the connecting elements 450 a, b. Next to each of thetwo driven pulleys 420, 421 two pairs of draw rolls 490 a, b, 491 a, bare provided that press a section of the loop against the driven pulleys420, 421. In order to shorten and/or lengthen the loop with respect toone or the other side of the symmetry axis 410, in this arrangement thepulleys 420, 421 have to rotate in opposite directions. For example, ifboth pulleys 420, 421 are activated by the respective drive units torotate in the directions indicated with arrows A and A′, the part of theloop on the left hand side of the symmetry axis 410 is shortened and thepart of the loop on the right hand side of the symmetry axis 410 islengthened. When the two pulleys 420, 421 are activated by therespective drive units to rotate in the directions indicated with arrowsB and B′, the right hand side of the loop with respect to the symmetryaxis 410 is shortened and the left hand side of the loop with respect tothe symmetry axis 410 is lengthened.

The relieve line 470 a, b follows this shortening and lengthening of theloop passively via the passive pulley 430. Both drive units that arecoupled with the pulleys 420, 421 comprise means to block in the case ofits failure. The blocking devices may be incorporated in the draw rolls490 a, b, 491 a, b. For example, if the drive unit coupled to the pulley421 fails, the draw rolls 491 a, b can prevent the loop from passing viathe pulley 421. In this case the loop is fixed at the driven pulley 421.Thus, an activation of the pulley 420 via the respective drive unitstill results in shortening or lengthening the loop with respect to oneor the other side of the symmetry axis 410, although only with speed andforce of the drive unit coupled to pulley 420.

The invention has been explained with respect to specific embodiments.The following claims define the scope of the invention.

The invention claimed is:
 1. An aerodynamic wind propulsion device forwatercraft comprising an aerodynamic wing connected to a steering unitlocated below the aerodynamic wing via a plurality of tractive lines, atleast one pair of active steering lines being connected to theaerodynamic wing at two points spaced apart from one another and beingcoupled to at least one drive unit at the steering unit, a tractivecable, a first end of the tractive cable being connected at the steeringunit to at least two of the tractive lines and a second end of thetractive cable being connected to a base platform, the aerodynamic winghaving an aerodynamic profile which generates an uplift force in thedirection of the tractive cable when the airflow direction is aboutperpendicular to the tractive cable, two passive steering lines, whereineach of the two passive steering lines comprises a lower section and anupper section, wherein a second end of the lower section of each passivesteering line is connected to a first end of the upper section of therespective passive steering line via a connecting member, wherein secondends of the upper sections of the two passive steering lines areconnected to the aerodynamic wing at two points spaced apart from oneanother, and wherein first ends of the lower sections of the two passivesteering lines are connected to each other to form a continuous passivesteering line section passing through the steering unit in order topassively follow a deformation of the aerodynamic wing induced bysteering forces applied to said at least one pair of active steeringlines.
 2. The device according to claim 1, wherein the at least onecontinuous passive steering line section is guided via a passive pulleylocated at the steering unit.
 3. An aerodynamic wind propulsion devicefor watercraft comprising: an aerodynamic wing being connected to asteering unit located below the aerodynamic wing via a plurality oftractive lines; at least one pair of active steering lines beingconnected to the aerodynamic wing at two points spaced apart from oneanother and being coupled to at least one drive unit at the steeringunit; and a tractive cable, a first end of the tractive cable beingconnected at the steering unit to at least two of the tractive lines anda second end of the tractive cable being connected to a base platform,the aerodynamic wing having an aerodynamic profile which generates anuplift force in the direction of the tractive cable when the airflowdirection is about perpendicular to the tractive cable, wherein thefirst end of the tractive cable is directly secured to a connectingelement located at the steering unit, at least one of the tractive linesis also directly secured to said connecting element, and said connectingelement is configured to transfer tractive forces between the tractivecable and said at least one tractive line.
 4. An aerodynamic deviceaccording to claim 3, wherein the tractive cable and the at least onetractive line are wound around said connecting element.
 5. Anaerodynamic wind propulsion device for watercraft comprising: anaerodynamic wing connected to a steering unit located below theaerodynamic wing via a plurality of tractive lines; at least one pair ofactive steering lines being connected to the aerodynamic wing at twopoints spaced apart from one another and being coupled to at least onedrive unit at the steering unit; a tractive cable, a first end of thetractive cable being connected at the steering unit to at least two ofthe tractive lines and a second end of the tractive cable beingconnected to a base platform, the aerodynamic wing having an aerodynamicprofile which generates an uplift force in the direction of the tractivecable when the airflow direction is about perpendicular to the tractivecable, wherein each of the two active steering lines comprises a lowersection and an upper section, a second end of the lower section and afirst end of the upper section being connected to each other via aconnecting member, and a second end of the upper section being connectedto the aerodynamic wing at one of the two points in distance, and firstends of the two lower sections of the two active steering lines beingconnected to each other in the region of the steering unit to form acontinuous active steering line section that is coupled to the at leastone drive unit and passing through the steering unit, characterized inthat a first relieve line is guided via a first relieve line pulleylocated at the steering unit, a first end of the first relieve line isconnected to the connecting member (350 a, b) of one of the two activesteering lines, and a second end of the first relieve line is connectedto the connecting member of the other one of the two active steeringlines.
 6. The device according to claim 5, wherein the first relieveline pulley and the at least one drive unit are located at distantpoints at the steering unit.
 7. The device according to claim 5,characterized in that a second relieve line is guided via a secondrelieve line pulley located at the steering unit, a first end of saidsecond relieve line is connected to the connecting member of a first oneof the two active steering lines, and a second end of said secondrelieve line is connected to the connecting member of the second one ofthe two active steering lines.
 8. The device according to claim 5,characterized by two steering lines or lower sections of two steeringlines, respectively, which are connected to each other in the region ofthe steering unit to form the relieve line or one of the relieve lines,respectively.
 9. The device according to claim 5, characterized in thatone or both of the relieve line pulleys is located coaxially to the atleast one drive unit at the steering unit.
 10. The device according toclaim 5, characterized in that at least one of the relieve line pulleysis a passive pulley.
 11. The device according to claim 5, characterizedin that the first relieve line pulley is coupled to a second drive unitsuch that activation of at least one of the drive units results inshortening the continuous active steering line section or the firstrelieve line, respectively, with respect to one side and lengthening thecontinuous active steering line section or the first relieve line,respectively, with respect to the other side of a symmetry axis of thesteering unit or the aerodynamic wing, respectively.
 12. The deviceaccording to claim 11, characterized in that each of the drive unitscomprises a blocking device configured to actively block the respectivedrive unit in case of drive unit failure.
 13. The device according toclaim 11, characterized in that the continuous active steering linesection and the first relieve line are connected to each other to form aloop.
 14. The device according to claim 13, characterized in that theconnecting member of at least one of the two active steering linescomprises a pulley, and said loop is guided via said pulley.
 15. Thedevice according to claim 14, characterized in that one of said driveunits is located below the other one at the steering unit, both driveunits are coupled to drive pulleys located within the loop, and the loopis preferably pressed against the upper drive pulley by two guidingpulleys located at the steering unit.
 16. A watercraft comprising anaerodynamic wind propulsion device, the aerodynamic wind propulsiondevice comprising: an aerodynamic wing connected to a steering unit viaa plurality of tractive lines, at least one pair of active steeringlines being connected to the aerodynamic wing at two points spaced apartfrom one another and being coupled to at least one drive unit at thesteering unit, a tractive cable, a first end of the tractive cable beingconnected at the steering unit to at least two of the tractive lines anda second end of the tractive cable being connected to a base platform,the aerodynamic wing having an aerodynamic profile which generates anuplift force in the direction of the tractive cable when the airflowdirection is about perpendicular to the tractive cable, and two passivesteering lines, wherein ends of the two passive steering lines areconnected to each other in the region of the steering unit to form acontinuous passive steering line section passing through the steeringunit in order to passively follow a deformation of the aerodynamic winginduced by steering forces applied to said at least one pair of activesteering lines.
 17. A method for using an aerodynamic wind propulsiondevice to start, land and fly an aerodynamic wing, the aerodynamic windpropulsion device comprising an aerodynamic wing connected to a steeringunit via a plurality of tractive lines, steering the aerodynamic wingwith at least one pair of active steering lines, the steering linesbeing connected to the aerodynamic wing at two points spaced apart fromone another and being coupled to at least one drive unit at the steeringunit, towing a vessel via a tractive cable, a first end of the tractivecable being connected at the steering unit to at least two of thetractive lines and a second end of the tractive cable being connected toa base platform, the aerodynamic wing having an aerodynamic profilewhich generates an uplift force in the direction of the tractive cablewhen the airflow direction is about perpendicular to the tractive cable,and securing the aerodynamic wing with two passive steering lines,wherein ends of the two passive steering lines are connected to eachother to form a continuous passive steering line section passing throughthe steering unit in order to passively follow a deformation of theaerodynamic wing induced by steering forces applied to said at least onepair of active steering lines.
 18. A method for controlling anaerodynamic wind propulsion device for watercraft wherein an aerodynamicwing is connected to a steering unit located below the aerodynamic wingvia a plurality of tractive lines, at least one pair of active steeringlines is connected to the aerodynamic wing at two points spaced apartfrom one another and coupling said at least one pair of active steeringlines to at least one drive unit at the steering unit, and a first endof a tractive cable at the steering unit is connected to at least two ofthe tractive lines and a second end of said tractive cable is connectedto a base platform, comprising the steps of: applying steering forces tosaid at least one pair of active steering lines, providing two passivesteering lines, each of the two passive steering lines connecting to theaerodynamic wing at two points spaced apart from one another, andconnecting ends of the two passive steering lines to each other in theregion of the steering unit to form a continuous passive steering linesection passing through the steering unit.
 19. The method according toclaim 18, characterized by the step of: guiding at least one continuouspassive steering section line via a passive pulley located at thesteering unit.
 20. The method according to claim 18, characterized bythe steps of: directly securing the first end of the tractive cable to aconnecting component located at the steering unit, directly securing atleast one of the tractive lines to said connecting component, andtransferring tractive forces between the tractive cable and said atleast one tractive line via said connecting component.
 21. The methodaccording to claim 20, characterized by the step winding the tractivecable and the at least one tractive line around said connectingcomponent.
 22. The method according to claim 18, comprising the stepsproviding each of the two active steering lines with a lower section andan upper section, connecting second ends of the lower sections and firstends of the respective upper sections to each other via connectingmembers connecting second ends of the upper sections to the aerodynamicwing at the two points in distance, connecting first ends of the twolower sections of the two active steering lines to each other in theregion of the steering unit to form a continuous active steering linesection that is coupled to the at least one drive unit passing throughthe steering unit, guiding a first relieve line via a first relieve linepulley (330) located at the steering unit, connecting a first end of thefirst relieve line to the connecting member of one of the two activesteering lines, and connecting a second end of the first relieve line tothe connecting member of the other one of the two active steering lines.23. The method according to claim 22, further comprising the steps of:guiding a second relieve line via a second relieve line pulley locatedat the steering unit, connecting a first end of said second relieve lineto the connecting member of a first one of the two active steeringlines, and connecting a second end of said second relieve line to theconnecting member of a second one of the two active steering lines. 24.The method according to claim 22, further comprising the step of:connecting a pair of two steering lines or lower sections of a pair oftwo steering lines, respectively, to each other in the region of thesteering unit to form the relieve line or one of the relieve lines,respectively.
 25. The method according to claim 22, further comprisingthe step of: guiding at least one of the relieve lines via a passivepulley.
 26. The method according to claim 22, further comprising thesteps of: coupling the first relieve line pulley to a second drive unit,and shortening the continuous active steering line section or the firstrelieve line, respectively, with respect to one side and lengthening thecontinuous active steering line section or the first relieve line,respectively, with respect to the other side of a symmetry axis of thesteering unit or the aerodynamic wing, respectively, by activating atleast one of the drive units.
 27. The method according to claim 26,further comprising the step of: actively blocking one of the driveunits, particularly in a mechanical manner, in case said drive unitfails.
 28. The method according to claim 27, further comprising the stepof: connecting the continuous active steering line section and the firstrelieve line to each other to form a loop.
 29. The method according toclaim 28, further comprising the steps of: providing a pulley at theconnecting member of at least one of the two active steering lines, andguiding said loop via said pulley.
 30. The method according to claim 18,further comprising the steps of: primarily accommodating appliedsteering forces by the active steering lines or the continuous activesteering line section, respectively, and primarily accommodatingsteering forces, forces resulting from the uplift force generated by theaerodynamic profile of the aerodynamic wing and/or forces resulting froma deformation of the aerodynamic wing by the first relieve line.